The diagram below shows how heat is lost and energy wasted in a house because of air getting into and out of the house.
Overall, heat loss ( energy escaping from a building) mainly through the roof, walls and vent .The warm air often rises and leaks out through the attic hatch and cold air usually enters the house from the crawl space.
Firstly, the air escapes from the top of the house such as the attic hatch, roof and upper rooms. Air is allowed to escape through the attic hatch, a small door or cover leading to the attic. Warm air rises; therefore, it often escapes through the roof. Also heat is lost through gaps around recessed light or bathroom, kitchen fan vents.
Secondly, air is also released from below the house mean of electrical outlets, the air can escape through small gaps around electrical outlets. Moreover, dryvent is an ideal place for cold air to enter the house. But cold air is also allowed to enter the house through the crawl space though its opening.
In conclusion,heat is mainly lost because of air leakage in different parts of the house
